This invention relates to gas turbine engines having stages of axial flow compressors and particularly to means for varying the rate of change of different stages of variable stators in the compressors.
As is well known, variable stators are desirable for improving performance of the compressor and there are many mechanisms available to achieve this end. However, what is most desired is to match the vane angle of the various stators with a specific schedule and the nature of the schedule is such that for a given engine requirement the angle of the stator and its schedule for different stages should be different. Thus, it is desireable to tailor each stage of stators to more closely match the schedule and to do so within the confines of the linkage system, bearing in mind the weight and complexity of the system. Exemplary of such system is U.S. Pat. No. 2,858,062 granted to R. C. Allen on Oct. 28, 1958 showing variable stator mechanism.
I have found that I can closely match the stator vane schedule of a turbine type power plant by having the actuator drive certain stages of the variable stator and having a linkage system driven by the driven states driving the linkage system of the other stator stages. The actuation system can be made more compact than heretofore systems by reversing the linkage connection to the stator vanes and nesting the actuator under the linkage system and applying a horizontal (relative to the engine's axis) rectilinear movement.